Optically bistable devices using the quantum confined Stark effect (QCSE), such as that shown in U.S. Pat. No. 4,754,132 by Hinton et al., having a common assignee with this invention, are useful in optical digital processing systems, such as optical digital computers and optical digital switching systems. The optically bistable devices are well suited to operate as logic gates or memory devices in these systems. However, optical bistable devices require a certain minimum optical energy input to switch from one optical state to another. Further, the time needed to switch states is usually inversely proportional to the optical signal input power available, provided the duration of the optical input signal is long enough to meet the minimum optical switching energy requirement. Therefore, the speed of the optically bistable device can be severely compromised if the magnitude of optical signal power applied is small. Since the amount of optical power available from practical laser sources is limited, the speed/optical input power tradeoff of optically bistable devices limits the number of these devices that can be placed in tandem to form complex logic networks, such as an adder used in an optical computer. Similarly, the size of large optical switching systems, using large numbers of optically bistable devices in parallel as part of the switching fabric, is limited. Therefore, the processing capacity of optical digital processing systems is limited by energy necessary to switch the optically bistable devices therein.